Purine metabolism in mouse ascites tumor cells. 1. Effect of performed purines on in vitro incorporation of glycine-2-C14.

Summary The effect of exogenous preformed purine compounds on the incorporation of glycine-2-C 14 into nucleic acids and acid-soluble nucleotides has been investigated in four ascites tumors: Ehrlich, Sarcoma 180, 6C3HED, and TA3. The action of some of these compounds differed from one tumor to another. The majority of compounds diluted incorporation of glycine into nucleic acids, but a few increased incorporation in some tumors. In TA3 cells, several of the compounds increased incorporation into RNA and decreased that into DNA. Acid-soluble adenine and guanine nucleotides showed the same effect (i.e., dilution or increase of specific activity) as the corresponding nucleic acid purine. Deamination products of adenine and guanine played an important role in magnitude of dilution, the pools of these compounds acting as traps for the carbon-14 from glycine-2-C 14 . Possible mechanisms involved in the effects of preformed purine compounds on de novo purine synthesis have been discussed.